An outspoken advocate for keeping Taunton State Hospital open will be in charge of the commission tasked with reviewing all the state’s mental health facilities and the way services are administered.

“There’s going to be a balance of folks just on the commission itself whose leanings are very strong in different directions,” said House Speaker Pro Tempore Patricia Haddad, D-Somerset, who was appointed Wednesday to serve as House chairwoman of the new Advisory Commission on Mental Health.

Another Taunton area legislator, Rep. Shaunna O’Connell, R-Taunton, will also serve on the commission.

The House and Senate passed legislation earlier this year to block the Patrick Administration’s plan to close Taunton State until a comprehensive independent study could be completed.

“I do think that bringing in somebody who’s independent and, for all intents and purposes, has no dog in the fight will balance my non-objectivity,” Haddad said.

The commission, Haddad said, will hire an independent contractor to produce the study. The consultant’s preliminary findings are due Dec. 28, and a full report is due April 30, 2013.

The commission has 20 members, including legislators, administration appointees and members of the Massachusetts Nurses Association, Massachusetts Psychiatric Society, Massachusetts Hospital Association and National Alliance of Mental Illness. Sen. John Keenan, D-Quincy, will be Senate chairman.